Method and apparatus for drawing wire glass



UNITED STATES PATENT OFFICE.

CLIFFORD A. BOWLEY, OF TOLEDO, OHIO, ASSIGNOR TO THE LIBBEY-OWENS SHEET GLASS COMPANY, OF TOLEDO, OHIO, A CORPORATION 0F OHIO.

METHOD ANI)v APPARATUS FOR DRAWING WIRE GLASS.

Application led February 17, 1921.

To all whom t may concern:

Be it known that I, (,Llrroao A. RowLEr, a citizen of the rUnited States, residing at Toledo. in the county of Lucas and State of (lhio, have invented new and useful Imrovements in Methods and Apparatus for rawing Wire Glass, of which the following is a specification.

This invention relates to a new and improved method and apparatus for drawing wire-glass from a bath of molten glass.

In the customary process of producing wircglass. or sheet glass with a layer of wire mesh embedded therein, a layer of molten glass is first rolled out on a suitable table. a sheet of wire mesh is then superposed thereon, and a second layer of molten glass rolled on above the wire. The sheet thus formed has molten and imperfect surfaces. and it' required to be transparent, must be subsequently ground and polished. as in the ordinary` practice of making plate glass. This is necessarily a long and experiv sive process. The present invention aims to produce transparci'xt sheet glass of a high quality. with an embedded wire mesh, by a. simple and continuous drawing process.

The details of the invention will be more clearly understood from the following description. taken in connection with the accompanying drawings showing one form of apparatus adapted to carry out this process.

In the drawings:

Fig. 1 is a longitudinal vertical central section through the apparatus, and

Fig. 2 is a partial end elevation of the intermediate bending roll, showing itsadjustable mounting.

At 1 is shown the discharge end of a continuous tank furnace. from which a flow of molten glass 2 is maintained to the shallow receptacle or draw-pot 3. Intermediate the length of receptacle 3 is an upwardly pro` jecting nozzle 4, containing a transverse slot 5. extending' vertically through the pot. This nozzle 4 does not extend entirely the width of the pot, but there is a, substantial passage around each end thereof, throu h which the molten glass flows to the far en 6 of the receptacle. Beneath the receptacle or dran--pot is the heating chamber 7, heated by suitable burners as indicated at 8. and th rough this chamber is a central partition Specication of Letters Patent.

Patented Aug. 8, 1922.

Serial No. 445,602.

9, having a slot 10 therethrough communieating with the slot 5 in nozzle 4. A sheet of wire mesh 11, is fed from a conveniently located supply roll 12, around roller 13 land up through the slot lll-5. Some ofthe heated gases from the chamber 7, pam through ports 14 in the partition 9, and up through slot 5 to heat the sheet of wire mesh 11 to a temperature comparable with that of the molten glass. The heating chamber 7 extends up around the far end 6 of the drawpot. and a lip tile or cover shield 15 encloses a portion of this end of the receptacle as shown in Fig. 1. A series of burners 16 directed in beneath this lip tile, through ports 1T act in conjunction with the heated gases from chamber 7 to maintain the molten glass in the far end 6 of the receptacle at a hi h degree of fluidity.

Eli/Iounted transversely of the pot, a short distance above the molten glass, on the furnace side of nozzle 4, is a horizontal internally cooled metallic roll 18. 'Roll 19 is carried in bearings 20 vertically adjustable by means of any suitable mechanism. As illustrated in Fig. 2. each bearing 2O is pivotally carried at the upper end of a threaded standard 21, en aged by a nut 22, supported by block 23. iy adjusting the nuts 22, the roll 19 may be raised clear of the molten glass 2` or may be lowered so that its lower surface dips slightly into the molten bath. Rolls 18 and 19 are internally cooled by means of circulating water. air or other fluid, a pipe connection for supplyin this fluid to roll 19 being indicated at 24, i 2. 'Phe roll 19 is preferably water coole to maintain it at quite a low temperature for reasons presently to be described., A third roll 25. similar to rolls 18 and 19, is mounted parallel to the others, at a point above and preferably somewhat beyond the receptacle 3, as indicated in Fig. 1.

While in operatioma mass of molten glass 26 is drawn u from the source 2` over cooled roll 18. and rom this mass of glass a sheet 27 is stretched laterally. This method of obtaining a lass sheet is substantially the same as set orth in the co )ending application of Crowley'. Serial umher 303,069, filed June l0, 1919. However, if desired, the roll 18 might be located higher above the molten glass 2, and the sheet drawn according to the process set forth in the Col burn patents, for example, 1,248,809, issued Dec. 4, 1917.

1n the apparatus as here shown, a vertically adjustable shear-cake 28 is located be tween the downwardly inclined arch 29 at the end of the furnace and the roll 18, and by properly adjusting shear-cake 28 the heated gases issuing from the furnace may be directed to the desired point on the rising mass of glassI 26.

The sheet 2T, instead of being drawn horizontally, is directed downward at an angle so that it will be tangent to the lower surface of the roll .1.9. The sheet of wire mesh 11, is drawn up over guide roll 30, and also directed tange'ntiall i toward the lower surface of roll 19, beneatli the sheet 2T. The sheet 2T. as it is drawn over and from the roll 18, and exposed to the cooler atmosphere becomes cooled and set, especially on its upper side. However, as the sheet is again brought down into proximity with the molten glass in receptacle 3, it is reheated and softened thereby, and by the heated gases confined between the molten glass and the sheet. To preserve the upper surface of the sheet, and the integrity of the sheet itself, a watercooler 31 is placed above the sheet, which together with the cooled roll 19, and the cooler air above the sheet keeps the upper surface of the sheet sufficiently cooled so that it ma pass beneath the cooled roll 19 without sticking thereto, or being injured thereby.

The lower surface of the sheet becomes so softened that the wire mesh, when drawn thereagainst becomes enmeshed therewith, and as the sheet and wire momentarily dip into and pass through the molten glass 2, a new coating of glass is drawn onto the lower surface of the sheet, enclosing the wire mesh, and a new and thicker sheet 32 is drawn up on the far Side of roll 19. This sheet 32 is drawn tangent to, and passes over the bending roll 25. As shown in the drawings the sheet 32 is drawn awa' from roll 19 at an angle of about 450 with the ver'- tical but it might be drawn vertically or at anyeonvenient intermediate angle. With the angles of draw as shown in the drawings, the thicker sheet.` with the enclosed wire is only bent through a very obtuse angle over roll 25, .which will tend to avoid undue bending strain on the sheet.

The heaters 16, which are directed against the glass where sheet 32 leaves the pot, coun teract the tendency of the sheet to pull away from roll 19, and also prevent too thick a coating being added to the sheet beneath roll 19K, By properly adjusting these heaters 16, tlie tinal thickness of the `sheet is properly regulated.

. Below the sheet. between rollsl 19 and 25, 1S a second cooler titl, adapted to adjust the temperature of the lower portion of the sheet, so that it may pass over roll 25 without sticking thereto or being marred thereby. Above the sheet, just before it reaches the roller 25, are burners 34, which reheat the sheet so that it may make the bend without fracturin f. rlhc sheet is drawn away horizontally V'rom roll 25, by the drawing and Hattening mechanism 35, which is only shown conventionally, and may be approxi mately of the forni used in the tolburn patents, referred to above. Between this drawing mechanism and the roll 25, is an intermediate supporting roll 3G. or rollers as may be necessary. while above lthe sheet is a rcheating chamber 3i", from which heat is dii'ectcd downwardly through ports 38, to rehcat the sheet and facilitate the flattening operation, and allow corrugations oi' wrinkles to be drawn out. The sheet, after passing through the drawing mechanism. goes` into and through a leer as is usual in similar drawing operations. An arch 39, over rolls 18 and 19, forms a partially enclosed chamber above these rolls, but it will be noted that the sides of this chamber are left open, both to provide access to the rolls and coolers, and also to allow thc cooler outer atmosphere to encounter the forming sheet and increase the possible speed of the drawing operations.

In commencing the operation ot' this apparatus, the roll 19 is tirst adjusted up clear of molten bath :3. and then b v means of :i bait` a sheet of glass is drawn over roll 18, under roll l5). over roll '.23 and thence through the drawingr mechanism 35. Provision is made for positively driving each of the rolls A18, l!) and :25. a sprocket chain drive for roll 25 being indicated at l() in l"ig. :2. After the operation of the apparatus is successfully initiated, any one or all ot' these rolls may be run as idlers, according as prevailing conditionsmay prove most desirable. A\ftcr sheet .)T is startcihlhc sheet of wire mesh ll is led under roll 19, over roll 2.3 and engaged by the drawing mechanism 35. The roll l!) is then adjusted down until it dips the desired extent into hath 2, so that the wire combines with the sheet, and the desired recoatiiig is obtained on the lower side. As the glass level in the bath mayv vary somewhat from time to time, the roll 19 may be adjusted accordingly.

lt will be noted that with this system, no attempt is made to draw two separate Sheets of glass and imite them about a sheet of wire mesh. The final sheet 32 is really drawn from beneath roll 19, although the upper half of this sheet has been previously formed and partially set to insure the substantial centering of the wire mesh within the sheet. Also the sheet is not bent through any sharp angles. Sheet :7 is not formed until it leaves the roll 18, and the bending angles about rolls 19 and 25 are each substantiall less than 900, By connecting on a new ro l of wire 12, when the first becomes exhausted, the operation may be made practically continuous.

Claims:

l. The method of drawing wire glass, wherein a continuous sheet of glass is drawn from a mass of molten glass and then dipped along with a sheet of wire mesh, into a molten bath of glass.

2. The method of drawing wire glass, wherein a continuous sheet of glass is drawn from a mass of molten glass, one face of the sheet bein maintained cool, whereas the other face is heated and dipped along with a contacting sheet of Wire mesh, into a molten bath of glass, wherein the sheet and wire are united, and a new sheet surface formed covering the wire mesh.

3. The method of forming wire glass, wherein a continuous sheet of glass, and a continuous sheet of wire mesh are drawn through a molten bath of glass, only the face of the sheet adjacent the Wire being exposed to the molten glass.

4. In an apparatus for drawing wire glass, a receptacle containing a bath of molten glass, means for drawin a sheet of 'glass therefrom, means for fee ing a sheet of wire mesh in under the glass sheet, and means for causin the wire and superposed glass sheet to (gip back into the molten bath, whereby the wire mesh becomes embedded within the finished sheet.

5, In an apparatus for drawing wire glass, a receptacle containing a bath of molten glass, a horizontal cooled roll mounted above the bath so that its lower surface dips slightly into the molten bath, and means for passing a continuous sheet of glass with a sheet of wire mesh therebeneath, under this roll.

6. In an apparatus for drawing wire glass, a receptacle containing a bath of molten glass, a horizontal cooled roll mounted above the bath so that its lower surface dips slightly into the molten bath, means for drawing a sheet of glass upwardly from the bath and then under this roll, and means for feeding a sheet of wire mesh in under the sheet before it dips into the molten bath.

7. In an apparatus for drawing wire glass, a receptacle containing a bath of molten glass, a horizontal cooled roll mounted in proximity to the molten bath, a second parallel cooled roll with its lower surface dipping slightly into the molten bath, means for drawing a sheet of glass over the first roll and under the second roll, and means for feeding in a sheet of wire mesh below the sheet between the two rolls.

8. In an apparatus for drawing wire glass, a receptacle containing a bath of molten glass, a series of parallel horizontal cooled rolls mounted above the receptacle, a sheet of glass being drawn laterally from the bath over the first roll, means for feeding in a sheet of wire mesh below this sheet, the sheet and wire being drawn laterally below the second roll and dipping into the molten bath, the sheet then bein drawn up over a third roll, a drawing mecanism for stretchin the sheet horizontally from the third ro l, means for cooling the upper side of the sheet between the first and second` rolls, and means for cooling the lower' side of the sheet between the second and third rolls.

Signed at Toledo, in the county of Lucas and State of Ohio, this 15th day of February 1921.

CLIFFORD A. RoWLEY.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,425,218, granted August 8,

1922, upon the application of Cliord A. Rowley, of Toledo, Ohio, for an improvement in Methods and Apparatus for Drawing Wire Glass, an error appears in the printed specification requiring correction as follows: Page 1, line 19,

for the word molten read mottled; and that the said Letters Patr-.xt should be read with this correction therein that the Same may oonform to the recorrl nf tue ase inthe Patent Oee.

ASigned and sealed this 19th d ay of September, A. D., 1922.

WM. KINNAN.

Acting Commissioner of Patents. 

